HK HK-4

The HK 4 pocket pistol was first introduced by Heckler and Koch in 1967 making it the first pistol produced by the company. Mass production of this pistol started in 1968 and continued until 1984. There were approximately thirty-eight thousand pistols produced during this time, serial numbered 10001 to 36550. Twelve thousand of these pistols were produced for the German police and other government agencies with the .32ACP caliber and are designated HK 4 P11 and serial numbered 40001 to 52400.

An additional 2000 were made around 1971 as a commemorative set with a golden trigger and gold name plate. The HK 4 was designated 4 because the pistol had the ability to be modular. This meant that the pistol could accommodate 4 different calibers by a simple replacement of the barrel, return spring, and the magazine. The four calibers that the pistol could use are: 5.6 mm rimfire/.22LR; 6.35x16SR/.25ACP; 7.65x17SR/.32ACP; 9x17/.380ACP (9 mm short). Most pistols were sold as .380ACP (9 mm short) or .32ACP; the other 3 calibers were sold as a kit with the appropriate barrels and magazines. This is a double action pistol meaning it is cocked and fired with the trigger for the first shot. It is thought that the design of the HK 4 is based on that of the Mauser HSc.

Calibers: 9x17/.380ACP (9 mm short); 7.65x17SR/.32ACP; 6.35x16SR/.25ACP; 5.6 mm rimfire/.22LR.

Length: 6 3 / 16 inches (157 mm)

Height: 4 21 / 64 inches (110 mm)

Width at Butt: 1 17 / 64 inches (32 mm)

Barrel Length: 3 11 / 32 inches (85 mm)

Sight Length: 4 49 / 64 inches (121 mm)

Weight of Pistol: 16.9oz (480g)

Weight of Magazine: 1.4oz (40g)

Magazine Capacity: 7, 8, 8, 8